Male sterility, types and utilization in hybrid seed production
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MALE STERILITY, TYPES & USES IN HYBRID SEED
PRODUCTION
PRESENTED BY-HIRDAYESH ANURAGI
ADM. NO. 2015A29DPhD GENETICS & PLANT BREEDING
CCS HAU HISAR, HARYANA
PRESENTED TO-Dr. M. S. PUNIA
PROFESSORGENETICS & PLANT BREEDING
CCS HAU HISAR, HARYANA
Course: Heterosis Breeding (GP-507)
Male sterility Manifestation of Male sterility History of Male sterility Need of Male sterility Detection of Male sterility Creation of Male sterility Classification of Male sterility Cytoplasmic Male sterility (CMS) Genetic Male sterility (GMS) Cytoplasmic genetic Male sterility (CGMS) Transgenic Male sterility Chemical hybridizing agents (CHAs) Applications of Male sterility in Hybrid seed production
Contents
Male Sterility
Male sterility is characterized by nonfunctional pollen grains, while female gametes function normally.
Inability to produce or to release viable or functional pollen as a result of failure of formation or development of functional stamens, microspores or gametes.
Main reason is mutation.
Sterile SterileFertile Fertile
Manifestations of Male Sterility
Absence or malformation of male organs.
Failure to develop normal microsporogenous tissue- anther
Abnormal microsporogenesis (deformed or inviable pollen)
Abnormal pollen maturation
Non dehiscent anthers but viable pollen, sporophytic control
Barriers other than incompatibility preventing pollen from
reaching ovule
History of Male Sterility
J.K. Koelreuter (1763) observed anther abortion within species
& species hybrids.
Genic male sterility has been reported in cabbage (Rundfeldt
1960), cauliflower (Nieuwhof 1961)
Male sterility systems have been also developed through
genetic engineering (Williams et al. 1997) and protoplast fusion
(Pelletier et al. 1995)
Male sterility were artificially induced through mutagenesis
(Kaul 1988)
Manual emasculation
Use of male sterility
Use of self-incompatibility alleles
Use of male gametocides
Use of genetically engineered “pollen killer”
genetic system
Several forms of pollination control
Why Male Sterility ???
Reduced the cost of hybrid seed production.
Production of large scale of F1 seeds.
Avoids enormous manual work of emasculation
and pollination.
Speed up the hybridization programme.
Commercial exploitation of hybrid vigour.
Creation of Male Sterility
Spontaneous mutations
Interspecific hybridization
Mutation induction (EtBr)
Genetic Engineering
Chemically induced male sterility (CHAs)
Detection of Male Sterility system
Whether a particular sterile genotype belongs to which MS
system can be detected by its progeny performance on crossing
with a few normal genotypes.
Trend-I- All progenies in all the rows may be sterile- CMS
Trend-II- Some rows may consist all fertile
Some rows sterile and fertile in 1:1 ratio- GMS
Trend-III- Some rows fertile. Some rows sterile and some
rows sterile and fertile in 1:1 ratio - CGMS
Classification of Male SterilityKaul (1988) Classified Male Sterility in three major groups
1. Phenotypic Male Sterility (Morphological) Structural or Staminal Male Sterility Pollen Male Sterility Functional Male Sterility
2. Genotypic Male Sterility Genetic Male Sterility (GMS)
Environmental Sensitive (EGMS)a) Thermo sensitive genetic male sterility (TGMS)b) Photoperiod sensitive genetic male sterility (PGMS)
Environmental non-sensitive Cytoplasmic Male Sterility (CMS) Cytoplasmic Genetic Male Sterility (CGMS) Transgenic Male Sterility (TMS)
3. Chemically Induced Male Sterility (CHA)
Pollen sterility: in which male sterile individuals differ from normal only in the absence or extreme scarcity of functional pollen grains (the most common and the only one that has played a major role in plant breeding).
Structural or staminal male sterility: in which male flowers or stamen are malformed and non functional or completely absent.
Functional male sterility: in which perfectly good and viable pollen is trapped in indehiscent anther and thus prevented from functioning
Phenotypic Male Sterility
Cytoplasmic Male Sterility (CMS)
Determined by the cytoplasm (mitochondrial or chloroplast genes).
Result of mutation in mitochondrial genome (mtDNA)- Mitochondrial dysfunction.
Progenies would always be male sterile since the cytoplasm comes primarily from female gamete only.
Nuclear genotype of male sterile line is almost identical to that of the recurrent pollinator strain.
Male fertile line (maintainer line or B line) is used to maintain the male sterile line (A line).
CMS is not influenced by environmental factors (temperature) so is stable.
CMS can used in hybrid seed production of certain ornamental species or in species where a vegetative part is of economic value.
But not for crop plants where seed is the economic part because the hybrid progeny would be male sterile.
This type of male sterility found in onion, fodder jowar, cabbage etc.
Utilization of CMS in Plant Breeding
Use of CMS lines
Transfer of CMS to new strains (Diversification)
Genetic Male Sterility (GMS)
Also called as nuclear male sterility.
Mostly governed by single recessive gene (ms) but dominant gene governing male sterility (safflower).
Origin: Spontaneous mutation or artificial mutations (Gamma rays, EMS) are common.
‘ms’ alleles may affect staminal initiation, stamen or anther sac development, PMC formation, meiosis, pollen formation, maturation and dehiscence.
S.No. Mutagens Crops1 Colchicine Jowar2 Ethidium Bromide Groundnut, Maize, wheat3 Acetone Barley
Types of GMS
Environment insensitive GMS: ms gene expression is much less affected by the environment.
Environment sensitive GMS: ms gene expression occurs within a specified range of temperature and /or photoperiod regimes (Rice, Tomato, Wheat etc.).
1. TGMS: sterility is at particular temperature e.g. In rice TGMS line (Pei- Ai645) at 23.30C (China). TGMS at high temperature is due to failure of pairing of two
chromosomes at metaphase was evident. This abnormality led to abnormal meiosis, abnormal or sterile pollens. Anthers were shriveled and non-dehiscence-Male sterile. However, these lines produced normal fertile pollen at low temp. Sensitive period : PMC formation to Meiosis
2. PGMS: Governed by 2 recessive genes. Sterility is obtained in long day conditions while in short days, normal fertile plant. Rice:- Sterile under Long day conditions (13 hr. 45 min + Temp. 23-
290 C) but fertile under short day conditions. Sensitive period: Differentiation of secondary rachis branches to
PMC formation
Inheritance & Maintenance Of male sterile line
Nuclear male sterility and hybrid seed production
msms Msms
P1P2
X
Msms
Male fertile
Male sterile Male fertile
msms
Male sterile
MsMs
Male fertile
X
F1 Msms
Male fertile
Cytoplasmic Genetic Male Sterility (CGMS)
CGMS is also known as nucleoplasmic male sterility.
Case of CMS, where a nuclear gene (R) for restoring fertility in
male sterile line is known.
R (restorer gene) is generally dominant can be transferred from
related strains or species.
This system is known in cotton, maize, jowar, bajra, sunflower,
cotton, rice and wheat etc.
Hybrid seed production using CGMS system
rr S RR F
Rr S rr F
rr S Rr S
rr S Rr S
rr S RR S
rr S Rr S
♂♀
♂♀
Strain A Strain B
×
×
♀ × rr F ♂
rr F ♂×
6-7 Back crosses
×RR S
1 2 1: :
CMS Restorer
Male fertile Non restorer (Strain-C)
Male fertile
× Male fertile Male sterile Discarded
Discarded
DiscardedMale sterile
Male sterile
DiscardedMale sterile ×
Self pollinatedMale fertile
Male sterile Self pollinated
Male fertile(Strain-C)
Male fertile(Strain-C) ♀
Male fertile
Restorer line R is crossed to Male sterile A
Male fertile F1 is crossed to Strain C in which R gene is to be transferred
Male fertility progeny is back crossed to strain C
× Male fertility progeny is back crossed to strain C
Male fertile progeny is self pollinated
Male fertile progeny is self pollinated. Individual plant progenies grown in next generation and non segregating progenies are selected
Transfer of Restorer gene ‘R’ to non restorer strain
Inbred A (Cytoplasmic Male Sterile)
Inbred B (Non restorer male fertile)
Inbred C (Cytoplasmic Male Sterile)
Inbred D (Non restorer male fertile)
♂
♂
♀
♀
rr S
rr f
rr S
RR S
Single Cross –I A×B
(Male Sterile)
Single Cross-II C×D
(Male Fertile)
rr S
Rr S
♀
♂
Double Cross (A×B) × (C×D)
rr S
Rr S
50%
50%
Production of Double cross maize hybrids using CGMS
(1:1 Segregation for Male Fertility & Sterility)
Sources of CMS & Restorer genes in some Crops
Crop species Cytoplasm Restorer Genes
Rice
CMS-CW O. spontanea
CMS-bo O. Sativa boroII (single dominant)
CMS-WA O. Spontanea (WA, four genes)
CMS-W18 O. rufipogon
Wheat (T.aestivum) T. timopheevi Rf1 and rf2
A. caudata -
T. Durum Aegilops ovata -
Maize
CMS-C Rf4
CMS-S Rf3
CMS-T Rf1 and Rf2
Crop species Cytoplasm Restorer Genes
TobacoN. Debneyi -
N. Megalosiphon -
N. bigelovii -
CottonG. Anomalum -
G. Arboreaum -
G. harknesii -
Sunflower PET-1 (H. petalaris) 2 polymorphic genes (Rf1, Rf2)
Jowar Milo or A1 Msc from kafir race
Bajra Tift-23A -
S.No. Crop Hybrid Variety Seed Production
1. Maize Ganga 101, Ganga 1, Deccan, Ranjit,
Trishulatha, DHM-107, DHM-109
CMS
2. Sorgum CSH1 CMS
3. Bajra HB1 CMS
4. Sunflower BSH1 CMS
5. Rapeseed PGSH51 CMS
6. Red Gram ICPH-8 GMS
7. Rice PRH1 CMS
Male Sterility based Hybrids in Important Crops
Recombinant DNA techniques for disturbing any or number of
developmental steps required for the production of functional
pollen within the microspore or for the development of any
somatic tissues supporting the microspores.
Transgenes for male sterility are dominant to fertility.
Also to develop effective fertility restoration system for hybrid
seed production.
Example: Barnase/Barstar system
Transgenic Male Sterility
Undesirable effects of the cytoplasm
Unsatisfactory fertility restoration
Unsatisfactory pollination
Spontaneous reversion
Modifying genes
Contribution of cytoplasm by male gamete
Environmental effects
Non availability of a suitable restorer line
Limitations of Cytoplasmic-Genetic Male Sterility
Barnase is extracellular RNase; barstar is inhibitor of barnase
(Bacillus amyloliquefaciens)
Plants with TA29 promoter-Barnase construct are male sterile
Those with TA29-Barstar are not affected by the transgene barnase.
Barstar is dominant over the Barnase
Fuse the barnase and barstar genes to TA29 promoter–TA29 is a plant
gene that has tapetum specific expression.
Cross male sterile (barnase) with male fertile (barstar) to get hybrid
seed, which now has both barnase and barstar expressed in tapetum
and, hence, is fully fertile
Barnase/Barstar system
Hybrid seed production using Barnase/Barstar system
CHA is a chemical that induces artificial, non-genetic male
sterility in plants so that they can be effectively used as female
parent in hybrid seed production.
Also called as Male gametocides, male sterilants, selective male
sterilants, pollen suppressants, pollenocide, androcide etc.
The first report was given by Moore and Naylor (1950), they
induced male sterility in Maize using maleic hydrazide (MH).
Chemical Induced Male Sterility
Properties of an Ideal CHA
Must be highly male or female selective.
Should be easily applicable and economic in use.
Time of application should be flexible.
Must not be mutagenic.
Must not be carried over in F1 seeds.
Must consistently produce >95% male sterility.
Must cause minimum reduction in seed set.
Should not affect out crossing.
Should not be hazardous to the environment.
S.No. CHAs Critical stage Crop species
1. Zink Methyl ArsenateSodium Methyl Arsenate
5 days before heading Rice
2. Ethephon/ Ethrel Depends on crop Barley , oat, bajra, rice
3. Mendok Depends on crop Cotton, sugarbeet
4. Gibberellic acid 1-3 days before meiosis Maize, Barley, Wheat, Rice, Sunflower
5. Maleic Hydrazide Early microsporogenesis Maize, wheat, cotton, onion
Some important CHAs
Hybrid Seed Production based on CHAs
Proper environmental conditions (Rain, Sunshine, temp, RH etc.)
Synchronisation of flowering of Male & Female parents.
Effective chemical emasculation and cross pollination
CHA at precise stage and with recommended dose
GA3 spray to promote stigma exertion.
Supplementary pollination to maximise seed set
Avoid CHA spray on pollinator row.
Conditions required:-
Advantages of CHAs
Any line can be used as female parent.
Choice of parents is flexible.
Rapid method of developing male sterile line.
No need of maintaining A,B&R lines.
Hybrid seed production is based on only 2 line system.
Maintenance of parental line is possible by self pollination.
CHA based F2 hybrids are fully fertile as compared to few sterile
hybrids in case of CMS or GMS.
Limitations of CHAs
Expression and duration of CHA is stage specific.
Sensitive to environmental conditions.
Incomplete male sterility produce selfed seeds.
Many CHAs are toxic to plants and animals.
Possess carryover residual effects in F1 seeds.
Interfere with cell division.
Affect human health.
Genotype, dose application stage specific.
Male sterility a primary tool to avoid emasculation in hybridization.
Hybrid production requires a female plant in which no viable
pollens are borne. Inefficient emasculation may produce some self
fertile progenies.
GMS is being exploited (Eg.USA-Castor, India-Arhar).
CMS/ CGMS are routinely used in Hybrid seed production in corn,
sorghum, sunflower and sugarbeet, ornamental plants.
Saves lot of time, money and labour.
Significance of male Sterility in Plant Breeding
Existence and maintenance of A, B & R Lines is laborious and difficult.
If exotic lines are not suitable to our conditions, the native/adaptive lines have to be converted into MS lines.
Adequate cross pollination should be there between A and R lines for good seed set.
Synchronization of flowering should be there between A & R lines.
Fertility restoration should be complete otherwise the F1 seed will be sterile Isolation is needed for maintenance of parental lines and for producing hybrid seed.
Limitations in using Male Sterile line
Applications of
Male Sterility in
Hybrid Seed Production
Male sterility system in Rice hybrid seed production
Male sterility: a condition in which the pollen grain is unviable or cannot germinate and fertilize normally to set seeds.
Male Sterility Systems (genetic and non-genetic):Cytoplasmic genetic male sterility (CMS)
Male sterility is controlled by the interaction of a genetic factor (S) present in the cytoplasm and nuclear gene (s).
Environment-sensitive genic male sterility (EGMS)Male sterility system is controlled by nuclear gene expression, which is influenced by environmental factors such as temperature (TGMS), daylength (PGMS), or both (TPGMS).
Chemically induced male sterilityMale sterility is induced by some chemicals (gametocides)
Two Commercial MS Systems for Hybrid Rice
SOURCE NURSERY Elite lines from different sources
TGMS Line Breeding To evaluate parents and make testcross B & R line Breeding Program
Pollinator line Breeding ProgamBreeder Seeds TESTCROSS NURSERY
To identify TGMS & P lines Hybrid Seed Production for OYTCore Seeds Premarily heterosis evaluation, 2 rows w/ parent Isolation Bags or hand-crossing
Foundation Seed RETESTCROSS NURSERY (OYT)Re-evaluate F1 hybrids Hybrid Seed Production for PYT
Certified Seeds Stage 1, 1 rep, 3 rows Isloated Net or bags
TGMS Line Release Preliminary Yield Trial (PYT)Stage 2, 1 rep, plot Hybrid Seed Production for AYT & NYT
Isolation BlockAdvanced Yield Trial (AYT)
Stage 3, 3 reps, plot
Hybrid Pilot Seed ProductionNational Yield Trial Isolation Block
Stage 4, 3-4 reps, muti-location, 2-years
Hybrid and R line ReleaseOn-Farm Trial (Strip Trial)
Flowchart of 2-Line Hybrid Rice Evaluation and Seed Production
TGMS and two-line hybrid
Based on the discovery of P(T)GMS mutant
Male sterility controlled by 1 or 2 pairs of recessive gene(s) Fertile
S-lineMultiplication
Critical Fertility Point
Critical Sterility Point
Reproductive Upper Limit
Reproductive Lower Limit
SterileF1 Seed
Production
Partial Sterility
Model of Sterility / Fertility Expression for TGMS Rice
Temperature
low
high
Advantage & Disadvantage of 2-line hybrid rice system
AdvantagesSimplified procedure of hybrid seed production Multiple and diverse germplasm available as parents
Any line could be bred as female97% (2-line) vs 5% (3-line) of germplasm as male
Increased chance of developing desirable & heterotic hybridsMultiple cytoplasm courses as female parents
DisadvantagesEnvironmental effect on sterility could cause seed purity
problem
Requirements for 3 Lines in CMS System
A-lineStable SterilityWell developed floral traits for outcrossingEasily, wide-spectum, & strongly to be restored
B-lineWell developed floral traits with large pollen loadGood combining ability
R-lineStrong restore abilityGood combining abilityTaller than A-lineLarge pollen load, normal flowering traits and timing
Elite CMS line SOURCE NURSERY Elite lines from different sources
To evaluate parents and make testcross B & R line Breeding Program
P line Breeding Progam
CMS BACKCROSS NURSERY TESTCROSS NURSERYBC2- BC4, CMS Evaluation To identify B, R & P lines R & P Line
Backcross CMS pairs (BC1)Premarily heterosis evaluation, 2 rows w/ parent Hybrid Seed Production for OYT
Isolation Bags or hand-crossingAxB Paircross RETESTCROSS NURSERY (OYT)Breeder Seeds Re-evaluate F1 hybrids
Stage 1, 1 rep, 3 rows Hybrid Seed Production for PYTIsloated Net or bags
AxB Increase Preliminary Yield Trial (PYT)Core Seeds Stage 2, 1 rep, plot
Hybrid Seed Production for AYT & NYTAxB Seed Production Advanced Yield Trial (AYT) Isolation Block
Foundation Seeds Stage 3, 3 reps, plot
AxB Seed Production National Yield Trial Hybrid Pilot Seed ProductionCertified Seeds Stage 4, 3-4 reps, muti-location, 2-years Isolation Block
A & B Line Release On-Farm Trial (Strip Trial) Hybrid and R line Release
Flowchart of 3-Line Hybrid Rice Evaluation and Seed Production
Advantage & Disadvantage of 3-line hybrid rice system
Advantages
Stable male sterility.
Disadvantages
Limit germplasm source (CMS, Restorer)
Dominant CMS cytoplasm in large area (WA)
One more step for parental seed production
Time consuming of CMS breeding
Male sterility system in Maize hybrid seed production
Different ways of inducing male sterility in maize
I. Manual/mechanical emasculation (detasselling)
II. Genic male sterility
III. Cytoplasmic genetic male sterility
IV. Gametocides
1. Genetic Male sterility
Male sterility determined by single recessive gene
40 loci involved have been identified (ms1 to ms52)
ms5 –cloned
Problem : impossible to maintain male sterile inbred
detasselling required
2. Cytoplasmic Male sterility
1. CMS-T (Texas) (Rogers and Edwardson, 1952)
Highly stable under all environmental conditions
Characterized by failure of anther exertion and pollen abortion
Susceptible to race T of the southern corn leaf blight - (Cochliobolus
heterostrophus = Bipolaris maydis)
Widespread use of T-cytoplasm for hybrid corn production led to
epidemic in 1970 with the widespread rise of Race T.
Toxin produced by C. heterostrophus = T-toxin.
Fertility restoration is sporophytic Rf1 (chr. 3) & Rf2 (chr.9) are responsible for fertility restoration
2. CMS-C (Charrua) (Beckett, 1971) Mutations in three genes viz atp6, atp 9 and cosII- confer CMS
phenotype Fertility restoration is Sporophytic Rf4, Rf5, Rf6 are responsible for fertility restoration
3. CMS-S (USDA) (Jones,1957) Sterility associated with orf355-orf77 chimeric mt gene Fertility restoration is Gametophytic Rf3 (chr. 2) are responsible for fertility restoration Plasmid like element S1 & S2
T-urf13 gene in T cytoplasm maize Mitochondrial gene T-urf13 is a unique chimeric sequence Effect of URF13 protein- Degeneration of the tapetum during microsporogenesis Disruption of pollen development leading to male cell abortion
Reversion to fertility
The reversion of CMS strain to male fertility is based on genetic change
Reversion can be spontaneous or mutagen induced
S-cytoplasm revert rather frequently to male fertility (than T & C). Maize-CMS Restoration of fertility system:
different classes of pollen grains are produced, but not all of them are viable
A X B(frfr) (frfr) ms mf
AB(frfr)ms
X C (FrFr) mf
ABC(Frfr)
mf
Triple Cross Hybrid C X D(frfr) (FrFr) ms mf
CD(Frfr)
mf
A X B(frfr) (frfr) ms mf
AB(frfr)ms
X
ABCD1
(Frfr)mf
1(frfr)ms
:::
Double Cross Hybrid
Types of Hybrids
Single cross hybrid (A×B)
Double cross hybrid (A×B)×(C×D)
Three way cross Hybrid (A×B)×C
Top cross (C×OPV)
Hybrid blends
Inter-population hybrids
Chance hybrids
Male sterility system in Bajra hybrid seed production
Hybrid seed production using CGMS Depends on the cytoplasm that produce male sterility and gene that
restores the fertility.
Steps: Multiplication of CMS (A) line Multiplication of Maintainer (B) line and Restorer (R) line Production of Hybrid seed (A×R)
Maintenace of A & B lines: Grow A line and its corresponding B line together in an isolated
plots. Isolation distance for A×B production fields is at least 1000m. A ratio of 1A:1B row is maintained. Pollens produced by the B line fertilize the male sterile plant (A)
and seeds produced thus Give rise to A line again.
Maintenance of R line: Pearl millet R line could be either an inbred line or an Open
pollinated variety which can be multiplied as variety.
Seeds of R lines are produced by multiplying seeds in isolated
plots having distance 1000m.
Any plant in the R line plot appearing different from true R
type should be uprooted or rogued out before anthesis.
Purity of the parental seed is very important because it affects
the quality of the hybrid seeds that is generated.
Scheme of hybrid seed production in pearl millet
Layout of hybrid seed production plot
Identification of potential hybrid parents (A,B and R lines)
Potential male and female parents for hybrid seed production are identified by crossing male fertile parent (Inbreds, variety, germplasm, breeding stocks in advanced generations) to a male sterile line (A line) and observing their corresponding hybrids in small plots of an observation nursery.
A few plants of each cross are subjected to the bagging test i.e. covering the few panicles with the paper bags before anthesis and observing the seed set under the bag after few weeks.
CGMS
A1 Tift 23 A (Most of the world hybrids contains A1 Blood), Burton,1958
A2, A3 Not stable cytoplasmA4 Derived from P. glacum subspecies monodii
Does not have effective restorerUsed in forage hybrid production
Male sterility system in Brassica hybrid seed production
Cytoplasmic male-sterile
Stamen (anther and filament) and pollen grains are affected It is divided into:
a. Autoplasmic Arisen within a species as a result of spontaneous
mutational changes in the cytoplasm, most likely in the mitochondrial genomeb. Alloplasmic
Arisen from intergeneric, interpecific or occasionallyintraspecific crosses and where the male sterility can be interpreted as being due to incompatibility or poor co-
operationbetween nuclear genome of one species and the organellar
genome. Another CMS can be a result of interspecific protoplast fusion
Raphanus or ogu system Polima or pol system Shiga-Thompson or nap system Diplotaxis muralis or mur system Tournefortii (tour) system Moricandia arvensis or mori system Chinese juncea or jun system
17 systems are available, only difference is the use of male sterile cytoplasmic sources differs for each system
Nap system– B.napuus cross b/w winter & spring var. pol system – B.napus var polima mur system--Diplotaxis muralis x B.campestris cv Yukina tour system– B.juncea collections
Various CMS systems
Ogu system:-
First discovered in Japanese radish (Raphanus sativus) by Ogura, 1968
B.napus genome was transferred into the back round of R.sativus (mst) through intergeneric crosses followed by back crossing with B.napus.
CMS seedling under low temperature showed chlorosis , because chloroplast of R.sativus is sensitive to cold, it is governed by cp-DNA , but mst is governed by mt DNA.
Protoplast fusion of R.sativus with B.napus carried out to have normal green plants with ogu CMS characterisitics
This system now has been used for developing alloplasmic male sterile line in B.juncea and B.campestris.
Genetic Male Sterility GMS is governed by two genes either recessive or dominant
genes(Kaul,1988)
One more dominant gene is associated with development of male sterility in B.napus type by means of transgenic male sterility
Chemical Male sterility
Enthrel – Brassica juncea
Zinc methy arsenate- B.napus
GA- B.oleracea var capitata
B.napaus
F1 interspecific cross
xRhapanus sativus
F1 Sterile
G-Rs
C-Rs
G-Bn
N-Bn
1/2G-Rs1/2G-Bn
C-Rs
mftmst
Doubling by colchince Fertile amphidiploid
1/2G-Rs1/2G-Bn
C-Rsmst
Development of Male sterile B. napus from R. sativus
1/2G-Rs1/2G-Bn
C-Rs
x G-Bn
N-Bn
G-Bn
C-Rs
B.napus
mst
BC3
Male sterile B.napus
mft
Development of Alloplasmic Male sterile Brassica campestris
xN-Bc
B.campestris
F1 interspecific cross
xG-Bn
S-Rs
G-Bct
N-Bc
1/2G-Bn1/2G-Bc
S-Rs
mftmst
G-BC
S-Rs
BC4
G-Bc G-Bc
Male sterile B.napus
Presently genetic male sterility (GMS), cytoplasmic male sterility
(CMS) and thermo sensitive genetic male sterility (TGMS) lines are
available in India.
Development of agronomically superior genetic male-sterile lines in
safflower in India have resulted in the development and release of
spiny safflower hybrids DSH-129 and MKH-11 in 1997 and NARI-
H-15 in 2005, the first non-spiny hybrid safflower NARI-NH-1 in
2001.
Male sterility system in Safflower hybrid seed production
Genetic Male sterility (GMS)
Complete male sterility ms1-ms5 = male sterility in sunflower recessive gene
Two types of g-mst
Type 1-gmst-Bloomington type Type 2-gmst-Modern type
Cultivated Sunflower variety Karlik-68(Dwarf 68)- two recessive genes msi1,msi2 (Stable and complete male sterile)
Partial male sterility –p mst
Male sterility system in Sunflower hybrid seed production
CGMS
H.petiolaris × H.annuus Repeated backcross of H.annuus results in cms1 which is extensively used mst in hybrid seed production of sunflower all over the world
H.giganteus× H.annuus Cms3( S cytoplasm source)
H.annuus subspp lenticularis × H.annuus CV commander
Indiana 1
Genetic Male Sterility (GMS): Reported in upland, Egyptian and arboreum cottons. In tetraploid cotton, male sterility is governed by both
recessive and dominant genes. However, male sterility governed by recessive genes is used in
practical plant breeding
All three types of male sterility occurs (g mst,c mst,gc mst) in cotton
Sixteen different genes in tetraploid cottons (13 in G. hirsutum and 3 in G. barbadense) and two in G. arboreum have been identified for genetic male sterility.
Sterility is conditioned by dominant alleles at five loci viz, MS4, MS7, MS10, MS11 and MS12 by recessive allele at other loci viz. msl, ms2, ms3, ms13, ms14 (Dong A), ms15 (Lang A) and ms16 (81 A).
Male sterility system in Cotton hybrid seed production
G. hirsutum line Gregg (MS 399) from USA is the basic source of GMS possessing ms5 ms6 gene for male sterility.
Genetic Male Sterility
CMS System
In case of CMS, the originally discovered CMS sources involving G. arboreum and G. anomalum cytoplasmic systems having interaction with ms3 locus were not found effective or stable under different environments.
The only stable and dependable CMS source under varied environment was developed through the utilization of G. harknessii. The complete genome of G.hirsutum was transferred into the G. harknessii cytoplasm.
A single dominant gene ‘Rf’ from G.harknessii is essential for fertility restoration.
Fertility enhancer factor 'E' for this CMS restorer system was obtained from a G.barbadense stock.
The harknessii system is reported to contribute to good agronomic properties and attraction to honey bees.
Sources of Male sterility in Cotton
Source of ms cytoplasm Nuclear genomeG. anomalum, G. arboreum, G. harknessii
G. hirsutum
G. anomalum, G. arboreum Heat sensitive , less stableG. harknessii × G. hirsutum Stable cms all over the environment New sources of CMSG. aridum Skovt. × G. hirsutum (D4)G. trilobum × G. hirsutum CMS 8 (D-8)G. sturtianum × G. hirsutum CMS-C1 New sources of CGMSG. anomalum x G. thurberi Cg-mst
Mutation G. arboreum, the first spontaneous male sterility mutant was identified
in variety DS-5
Chemical based male sterility FW 450(Sodium B-Dichloro-iso-butyrate) MH-30 (Maleic hydrazide) Ethidium bromide
Male sterility based hybrid Production GMS system. CPH2 (Suguna), First hybrid based on GMS released at
CICR, RS, Coimbatore G. harknessii based cms with fertility restoration gene sources were
used in developing the hybrid CAHH 468 (PKV Hy-3).
Cytoplasm Nuclear genome ReferenceS.acaule (4X) S.tuberosum Lamm,1953S.chacoense(4X) S.tuberosum Rammanna and Hersmen(1974)
S.phureja(2x) S.tuberosum Magoon et al.,1958b
S.stoloniferum(4x) S.tuberosum Ross (1961)
S.Verrucosum(2X) S.tuberosum Abdalla (1970)
Inter-specific Hybridization
Male sterility system in Potato hybrid seed production
FW 450(Sodium B-Dichloro-iso-butyrate) MH-30 (Maleic hydrazide) Ethidium bromide
Chemical mutagens
Development of Male sterility
Genome transfer S cytoplasm is in the genome of fr genes
Unreduced Gamete ProductionS.tuberosum (2x) × S.tuberosum (4x)
Protoplast Fusion S cytoplasm is retained
Di haploid
S.tuberosum (4x) × S.phureja (4x)
(2x) (2x) F1 (4x)
Anther culture
DiHaploid (2x)
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